I was up in the Cairngorms surveying ptarmigan last week, Rock Ptarmigan Lagopus muta, and they are well named for they are seldom seen far from rocks in the Scottish hills.
Their breeding season was about two-three weeks later than usual this year due to prolonged and extensive snow-lie. Many of the birds did not have any chicks, perhaps after failing to lay eggs or losing eggs or young? Others had very small broods of only single chicks compared with the usual average of five or six chicks of about two weeks age - the age of the chicks that I did see.
Several hens which had no young had joined cock post-breeding moulting flocks and were roaming through the boulder fields skulking quietly amongst the rocks. When moulting, these birds typically prefer to walk away from any intruder as they probably feel more secure doing so while they have some flight feathers missing or only partly-grown.
They seemed so at home in the boulders, hopping and skipping over them with no effort at all. At times they were running over what to me was very awkward ground to walk over. They run over any open ground or large open slabs as they feel exposed to predators, then slow down once secure amongst the jumbled rocks again.
I left them to it and watched a snow bunting for a while, singing from the top of a large boulder. And in the meantime the ptarmigan settled down to rest amongst the rocks, disappearing to my eye as their colours blended with those of the lichen-covered boulders.
Here are a few shots of a hen showing her deft footwork on the boulders